RSS feed 方面，如果还是用的 Yahoo! Pipes 那个，应该不用怎么改动，原来直接在网页上点 RSS 按钮订阅的请切换到 Pipes。

以书签形式收藏了某些文章的同学请尽快更新书签，或者把文章下载到本地保存。原来的域名和空间还有两百多天的有效期。我暂时不打算绑定域名（因为这样做需要备案），而且 Yo2 的 url 形式跟原来我用的也不尽相同，所以过去的 url 肯定不能再用了。

A new preprint article pop up in Ecological Modelling’s RSS feed today, showing a case study using ecological network analysis in the functional assessment of an estuary ecosystem. I was wondering what is ecological network analysis, and how it assesses a system’s function, so I read on.

It turns out that the technical details of ecological network analysis involves food web and information theory. The former I have some understanding, but the latter is too complex for me as a newcomer to dwell in the late night. Here is the paper describing the ECOPATH II model used by the preprint article. Judging from its number of being cited, many people must have used it successfully in their studies. However, the authors of the model acknowledged that it is based on a steady-state assumption, which arguably hardly exist in any real ecosystem, thus they recommend it used only in snapshot descriptions of ecosystems.

I doubt such a model can be used to describe ecosystem functions, considering that ecosystem functions do not present themselves in full in a “snapshot”. The authors of the preprint article seem confident that this method at least identify ecosystem functions based on the goal of management defined by researchers and decision makers. But I think the role of artifacts and stochasticity in this is too significant to let pass.

In preliminary studies, I think this method has its use. If researchers can establish the food web structure and nutrient dynamics in a system, we may use this method to identify some key species or functions of the system. However, its results must be iteratively put back to our picture of the system, to check whether it conforms the dynamics and management goals. The method seems to work only with “pure” ecosystems, while many researchers have moved on to study social-ecological complex systems. I wonder if this is the reason why the method has been silent for all these years.

Christian, R., Brinson, M., Dame, J., Johnson, G., Peterson, C., & Baird, D. (2009). Ecological network analyses and their use for establishing reference domain in functional assessment of an estuary Ecological Modelling DOI: 10.1016/j.ecolmodel.2009.07.012

Christensen, V., & Pauly, D. (1992). ECOPATH II — a software for balancing steady-state ecosystem models and calculating network characteristics Ecological Modelling, 61 (3-4), 169-185 DOI: 10.1016/0304-3800(92)90016-8

Recently I am help doing a study on dust transport and deposition concerning central and northern Libya. A geochemical study by my mentors suggest that some of the dust in Hun and Sebha, even some in the coastal areas, may be from the Bodélé, which is the largest source of dust in Libya. This preprint article on PNAS, therefore, is of special interest to me.

However, if the authors of the paper are right about the transport mode of dust from Bodélé, our story may prove wrong. The authors claim that the prevailing direction of the dust transport from this area is towards the west in winter, which is also the maximum of dust output in a year in the area. But our study area shows a constrasting trend: lowest dust deposition both by ground data and remote sensing, in winter, and it is to the north of Bodélé. The summer transportation, if any, may contribute very little to our study area, limited both by transport and production.

The MODIS brightness temperature difference (BTD) data is being derived, which can provide us a picture of dust plumes for major dust events. We are also looking at the geochemical properties and meteorological data around the area. Combining these data, hopefully, can provide more information on the transport mode in our study.

In the PNAS paper, the authors point out that the Bodélé area may be a “tipping element” in the context of climate change, due to its dominant position in the output of dust and its location. Some climate models suggest that the area may become wetter, yet the wind will be strengthened. As a result, it is really difficult to tell how the dust output will be influenced by climate change at the moment. Will we have more or less dust from Bodélé? This will be an interesting problem, as dust from this area interacts with many large-scale systems. It is a wonder, considering that the Bodélé Depression is so small. The difficulty is that we only have inaccurate model and incomplete data for this area, and for the North Africa. New remote sensing technology such as SEVIRI (imagine quasi-MODIS resolution images every 15 minutes, very cool) may partly solve the problem, but more geochemical and meteorological data are essential to answer the complex dust question.

Washington, R., Bouet, C., Cautenet, G., Mackenzie, E., Ashpole, I., Engelstaedter, S., Lizcano, G., Henderson, G., Schepanski, K., & Tegen, I. (2009). Tipping Elements in Earth Systems Special Feature: Dust as a tipping element: The Bodele Depression, Chad Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.0711850106

OHARA, S., CLARKE, M., & ELATRASH, M. (2006). Field measurements of desert dust deposition in Libya Atmospheric Environment, 40 (21), 3881-3897 DOI: 10.1016/j.atmosenv.2006.02.020

I have the impression that someone on researchblogging.org has already used a similar title to describe the link between rising temperature and vectors of contagious diseases. But this article has pointed out another layer of complexity existing in the temperature-disease connection. Turns out that malaria does not necessarily need hot weather, a reasonably warm mean temperature with high diurnal temperature range (DTR) will do.

The malaria parasites will need to develop to a certain stage before it can actually infect people. And this takes time. Researchers already know that the length of the period depends on the environmental temperature, and accordingly they predict that the risk of malaria epidemics will increase, as the mean temperatures in many areas rise. It takes less time for the parasite to develop, and the carrier — mosquitoes — has more time to bite and infect people before it dies. If the period of development is so long that it almost equals or even exceeds the mosquito’s life expectancy, very little harm is done.

The authors of the PNAS paper find that the period of development depends not only on daily mean temperature, but also on the temperature range through the day. In areas with relatively low temperature, given the same mean temperature, malaria parasites in areas with higher temperature variation in a day need significantly shorter time to develop. Similarly, high DTR in areas with high temperature may slow down the development. Thus the authors say the picture of malaria and similar epidemic in a global climate change context may be more complex than we previously think.

The immediate lesson is that we may have overestimated the additional risk in some tropical areas, and underestimated that in some temperate regions. But exactly what are these areas asks for studies at local scale.

Paaijmans, K., Read, A., & Thomas, M. (2009). Understanding the link between malaria risk and climate Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.0903423106

今天从超市回来的时候, 在路上被一个慈眉善目的老爷爷拦住, 问我是不是本市 大学的学生, 然后又问我学的专业. 知道了我学地理并是个二把刀的生态学学生 以后, 我们就开始聊人类对环境的破坏问题.

在英国呆过一段时间的同学都知道, 一般在街上找人说话的, 通常不是传教的就 是代表某慈善组织劝你捐钱的, 或者这两者的交集, 但是我实在太久没跟英国人 说过话了, 心想说两句也是好的, 就扶着自行车, 背着菜篮子, 在步行街中间和 他聊起来.

老爷爷感叹了一番人类对环境的破坏, 痛斥了超市里连个苹果都要从南非千里迢 迢运来的不合理性, 然后回忆了自己小时候自己种土豆吃的时光. 但是我很不解 风情地说, 要是人人都自己种土豆吃, 那谁有空办学校和读书呢? 老爷爷就乐了. 我背的是个布口袋, 老爷爷大概没看出我刚从超市出来. 其实我口袋里就装了一盒 美国产的樱桃, 说出来怪囧的.

老爷爷接着说，你说几千年前人就知道水循环的道理了，怎么进化了几千年，反 而越发贪婪和不爱地球了呢. 我心说进化几千年算个啥. 然后我说别说几千年, 物种争夺资源的天性是始终伴随着进化的, 人类的这个问题比较突出不过是因为 人跟生态系统解耦的程度高一些而已. 何况进化一词字面上暗示进步, 其实方向 是随机的, 变化也无所谓好坏, 只有能否适应环境的区别而已.

老爷爷又自顾自地说, 你看啊, 你说到进化, 进化是有条件的, 如果没有数亿年 持续不断的水循环, 进化的历史是不可能的. 而水循环和太阳带给我们能量的过 程, 这是多么精巧的设计啊! 我心里暗叫不好, 该不会是宣传 ID 的吧, 不过不 好立即就给人家扣上这么一顶帽子, 如果他是正统的神创论者大概也不乐意被当 作 ID 论鼓吹者, 于是我就继续跟他聊下去.

然后他就把书拿出来了. 英国的天气一个特别有利于传教的地方在于, 夏天经常 不热, 穿个大衣出来也不是特别奇怪, 于是你就不知道什么时候他们会突然 biu 地一下变出一本<圣经>或者别的什么书要你看. 我随便翻了一翻, 不能确定是神 创论还是 ID, 但基本是否定进化论的. 于是我就拿着书跟他讲进化论的理论和证 据等等. 另外还扯了一堆月球火星之类有的没的. 然后我说我不反对作为对精神 世界的探求的宗教, 科学有它需要解答的问题, 宗教也有它要解决的问题, 而如 果它们跨界试图解决它们领域之外的问题, 结果很可能是可怕的. 当时没想起好 的例子, 就随便说了人的平等与差异如果完全试图用科学来解释, 结果就是给纳 粹式的优生学张目, 其实如果举人的感情不能简单地用科学还原为激素和神经元 的相互作用这个例子, 可能更能说明这个道理. 我借用了 Contact ¹的立意, 即完整的真相需要科学和宗教携手去发现, 这也是 Short Introduction 系列 Science and Religion ²的观点. 没想到老爷爷提醒我历史上因宗教而杀人 的事例不少. 于是我怀疑他信 ID, 虽然当时我没多想.

后来又杂七杂八聊了一堆, 比如达尔文写<物种起源>与他的信仰问题, 还有上帝 与自然规律的关系等等. 眼看将近正午, 老爷爷知道没法说服我, 就收起书走了. 我们友好地互道再见.

我现在还是不能确定, 或者不愿承认, 这位老爷爷是主张 ID 的. 我看过主张在 学校科学教育中引入 ID 的书³, 其作者们虽然号称是大学教授, 写出来的 文字却未必比这位老爷爷的话更理性. 老爷爷至少在言谈中表现出了对事实的尊 重, 哪怕这与他相信的东西不一样. 这次对话更像是表达意见而非交锋.

虽然谈话没有改变我们双方的不同看法, 但是不难想象这样一位书卷气浓厚的老 爷爷要说服没有经过系统科学教育, 或者自己对这类问题思考不多的人会是多么 容易. 失败的传教和失败的科学教育, 共同点在于它们一上来就要求记诵它们所 宣称的真理. 老爷爷的传教没有成功, 则在于他试图用我的专业拉近我与他的观 念的距离, 但我的知识储备让我能够看出他的话语中牵强附会的地方. 我不知道 什么是成功的传教, 但它大概要建立在社会所接纳或追求的价值体系之上, 这个 价值体系因时期而异, 中世纪是忠君爱王, 现在讲究自由意志, 但大体上脱离不 了基本的道德原则. 成功的科学教育, 大概也需要类似的一个价值体系, 但科学 本身是没有道德性的, 所以这个体系的建立会困难一些. 但科学教育有一个优势, 在于人的求知欲可说是与生俱来的, 后天要掌握的不过是描述现象, 提出假设和 证明的方法, 这些相对来说都是比较容易规范化的. 于是乎, 科学教育所需要的 价值体系的基础, 我想可以建立在 1) 对自身认知能力和局限的认识; 2) 对现象 的准确描述; 3) 对理论的产生, 作用和局限性及谬误的认识和相关的实践; 4) 作为生产活动和文化的科学; 以及 5) 科学与现实世界的联系这 5 个逐级拔高的 支点上.

The DIVA (Dynamic and Interactive Vulnerability Assessment) tool is a modular “discussion-making” tool developed by the EU funded DINAS-COAST project. The tool is used to facilitate the assessment of vulnerability in coastal areas. It tries to address these drawbacks of similar tools and models:

• Low resolution and obsolete data sources;
• Limited number of scenarios;
• Unable to identify causes of vulnerability except for sea-level rise;
• Not considering social-nature interaction and feedback;
• arbitrary and simplistic assumptions about adaptation.

The main characters of the DIVA tool are:

• Integration of multiple disciplines in the study and simulation of vulnerability issues;
• Modular architecture allows constant update and evolution of the tool, to adapt to changing contexts and adaptation/succession;
• Non-expert friendly interface, designed to help answer questions asked by stakeholder and researchers from a wide range of groups.

Using a relational geospatial information database as its foundation, the DIVA tool can be considered as a set of modules, each addressing a process contributing to the vulnerability of coasts, governed by a framework that describes the conceptualization of the system in question. Only processes that conform to the general conceptualization can be modelled.

The development of the tool is an interesting case study of distributed software engineering. The authors of the modules belong to different institutions all over the Eurasia continent, and collaboration has to be carried out with email, Internet and phone. During development, the developers cannot even tell what the interfaces of the modules would be. To coordinate the efforts, the whole consortium used an ontology (conceptualization) of the system, and stored it as XML in a central location. The ontology then guides developers to establish algorithms and data structures. The module then goes to a stand-alone mode test. Finally, the linkage of the module with others and the whole model are tested.

Judging from the difficulties of developing such a complicated project, the DIVA tool is an exceptional success. However, the modular approach also have its own problems. The most significant one is that one module’s underlying theory and implementation are often not concerned by other experts, and the relationships between modules are not always well understood. This perhaps is why the author of the article calls the DIVA tool “transdisciplinary” instead of “interdisciplinary”.

An important issue in vulnerability studies is the cross-scale interactions. The DIVA tool cannot address this issue well, but the authors are pretty sure that the modular structure of the tool allows these features to be easily added. It is natural to consider the possibility to expand the tool to other vulnerability problems, such as desertification or energy dependency, but this may need a new framework. It is also not clear whether the DIVA framework supports modelling of long-range interactions.

The authors do not expect the DIVA tool to answer all vulnerability questions. They call it a “discussion-making” tool instead of a “decision-making” tool. The ability to better incorporate stakeholders in vulnerability study is eagerly needed in all kinds of socio-ecological systems. It would be wonderful to see more DIVA-style tools appear.

Hinkel, J., & Klein, R. (2009). Integrating knowledge to assess coastal vulnerability to sea-level rise: The development of the DIVA tool Global Environmental Change, 19 (3), 384-395 DOI: 10.1016/j.gloenvcha.2009.03.002

Adger, W. (2000). Social and ecological resilience: are they related? Progress in Human Geography, 24 (3), 347-364 DOI: 10.1191/030913200701540465

The climate change deniers say that climate change and relevant concerns are a fad. Well they must be wrong. From my personal experience I was reminded of the climate change scenario in 1980s — right, before I went out of the kindergarten — and that was like 20 years ago. And scientists today are using data that are accumulated continuously in the past 20 years to study the impact of climate change.

One instance is this preprint published on the PNAS website. The authors creatively used the fixed-temperature pH data, avoiding problems like the change of H₂CO₃ equilibria with temperature, and making the seasonal trend pronounced. It is pointed out that there is a trend of decreasing pH at sea surface, and more importantly, the seasonal pattern of water change between surface and sub-surface zones of the ocean may be a profound factor in a more complicated ocean acidification picture.

There are drivers at different scales at play here, causing diurnal, seasonal and annual variabilities of the ocean acidity. The authors mentioned a strong pH negative anomaly in 1998, which causes me to think whether there could be some cross-scale interactions, such as El Nino, also at play.

Another thought that occurred to me is that the dissolved organic carbon may be a slow variable in the ocean system. Of course I am not an oceanographer and this is just a wild guess. But if there is any oceanographer reading, would you care to explain the circulation of inorganic carbon in the ocean? We all know the acidity in the ocean is slowly increasing, but if there is an accumulation process of inorganic carbon that we do not know, one day it is going to give us a bigger surprise given adequate temperature and mixing conditions.

John E. Dore, Roger Lukas, Daniel W. Sadler, Matthew J. Church, & David M. Karl (2009). Physical and biogeochemical modulation of ocean acidification in the central North Pacific Proceedings of the National Academy of Sciences of the United States of America DOI: 10.1073/pnas.0906044106

In real life scenarios, the problem with active adaptive management is what should the decision makers and stakeholders learn from the experiments and what kind of institution is really “adaptive”.

A new article appearing in Global Environmental Change is another attempt to tackle these questions. The author argues that often policies are not adaptive in that they are just trying to adjust actions according to the effect, without further questioning the underlying constraints and contexts of the action. To be adaptive and help build resilience, the governing regime should adopt multiple levels of learning, starting from refinement of actions, to questioning the frame of reference and underlying assumptions, to transform the structure of context and established values and norms. If the institution is only limited to the first loop of learning, it may finally encounter some restraints that limit its adaptive capacity. As a result, in the face of larger environmental or socioeconomic changes the institution will fail to maintain the resilience of the complex system.

The author further points out that a government-dominated institution would not be flexible enough to adopt the second- or third-loop learning, which requires the change of the whole actor network, regulations and the structure of the institution. As a complement of the “formal” institution, the “informal” institution featuring stakeholder participation, more flexible regulation, and local knowledge should be introduced. It is noted that such kind of informal institutions often lack a voice or ability to take actions in large-scale projects, thus a hybrid institution combining the executive power of formal institutions and the flexibility of informal institutions is called for.

The trend of more active informal network, or “shadow network”, may see the hierarchy in environmental management more diminished. How to guarantee the voice of the informal institutions heard may not be a major problem in industrialised countries, but will be one for minority groups and marginalised communities in developing countries. To establish a context around their point of view will be an interdisciplinary challenge.

Claudia Pahl-Wostl (2009). A conceptual framework for analysing adaptive capacity and multi-level learning processes in resource governance regimes Global Environmental Change, 19 (3), 354-365

Carl Folke, Steve Carpenter, Thomas Elmqvist, Lance Gunderson, C S Holling, & Brian Walker (2002). Resilience and Sustainable Development: Building Adaptive Capacity in a World of Transformations Ambio, 31 (5), 437-440

今天在学校听了来自 UC Irvine 的 Bradford A. Hawkins 教授的一个讲座。 据说Hawkins 是生物地理学和宏观生态学方面的大牛，可惜听讲前自己没有做足功课，虽然讲座是近期少见的信息量大、富启发意义的题目，却没有听得太明白。 好在回来搜论文找到了 Hawkins 等即将发表的关于同一个研究的论文。

Hawkins 等人使用了墨西哥以北的北美地区夏季和冬季的蝴蝶物种丰度资料，将蝴蝶亚科按照分布范围分成热带和非热带两部分进行讨论。从物种丰度在纬度方向上的梯度看，热带类型的蝴蝶物种明显地表现出夏季向北迁徙或者 recolonize 的趋势；而非热带类型的蝴蝶则很少表现出有长距离的迁移。而以亚科在包括弄蝶总科 Hesperioidea 和凤蝶总科 Papilionoidea 的整个谱系树上的遗传距离（Mean Root Distance, MRD）来看，北美地区靠近热带的南部物种间的距离较短。 如果蝴蝶起源于热带的假设成立，这说明非热带物种多是适应了较寒冷气候的进化支。

根据对 8 个可能因素的回归分析，热带物种的丰度跟温度正相关，与热带地区的距离成负相关。非热带物种丰度与温度的关系更复杂一些。虽然夏季温度还是与物种丰度正相关，冬季温度较高的地区物种丰度却不一定更高。作者提出的解释是对于适应了较寒冷环境的蝴蝶物种，冬季温度有一个最适范围，高于这个范围的温度可能会扰乱休眠期的蝴蝶的生理活动，导致其数量减少甚至局部灭绝。一些对北半球气候变化造成的物种向北迁移的现象可以作为这个观点的一个注脚。

作者在文末指出形成北美蝴蝶多样性梯度的根本原因在于蝴蝶的热带起源和第三纪中期以来的长期气候变化模式。Hawkins 今天在讲座中进一步指出在欧洲、澳大利亚、智利、南非等地区也都发现了类似的梯度分布，可见他的观点具有相当强的解释力。这一研究不仅能用来解释北美现有的蝴蝶多样性梯度，也有可能被用来进一步研究蝴蝶各亚科和物种的进化和迁徙模式。这种研究方法理论上说也应该可以应用于其它起源于热带的物种，但对于蝶科的生活史、习性和物种分布的完整研究是做出这样研究的前提条件，不知道在无脊椎动物中还有哪些物种有这样完整的研究记录。

这一研究也揭示了气候变化引起的冬季温度变化将会给非热带蝴蝶物种带来的问题。从北美地区来看，热带物种可能不会仅仅因为温度上升就迁往更朝北的地区，但非热带物种聚集的地带可能会向北移动，欧洲也是如此，甚至有可能在热带和非热带物种区之间形成一个空白地带，也许会对这些地区的农业和林业产生影响。

Hawkins, B., & DeVries, P. (2009). Tropical niche conservatism and the species richness gradient of North American butterflies Journal of Biogeography DOI: 10.1111/j.1365-2699.2009.02119.x

The approach cannot tell what really is cross-interacting with other variables, yet. And being a statistical method, it requires a huge amount of data. Perhaps by regression of multiple series and types of data, and with the aid of conceptual models, this approach can bring more insight into the system.